Summary:
Features include minute, white to nearly colorless, obconic fruitbodies occurring on Sphagnum squarrosum Crome. Its mycelium penetrates and parasitizes mucilaginous cells on that species. Randomly collected samples of Sphagnum squarrosum are usually infected with D. schimperi, but fruitbodies are less common.
Collections of Sphagnum squarrosum infected with D. schimperi were examined from BC, OR, AB, MB, NB, NF, NS, NT, ON, PE, PQ, SK, YT, AK, CO, ME, MT, PA, WI, Greenland, Finland, Sweden, Japan, Russia, and Ukraine (Redhead).
Upper surface:
fruitbody 0.02-0.08cm across, obconic; white to nearly colorless; bald; spore-bearing surface flat to slightly convex
Stem:
without stem, but attached by a web of mycelium to host''s phyllids
Microscopic:
spores 15-20 x 4.5-5.2 microns, cylindric to vaguely elliptic, sometimes inequilateral, smooth, inamyloid, colorless, thin-walled, often with two droplets; asci 8-spored, 81-85 x 9-11 microns, cylindric to narrowly elliptic, slightly tapered or rounded at top, inoperculate, apex thickened and refractive, and faintly amyloid with a more prominently amyloid, truncated funnel-like central pore when fresh, with a short narrowed pedicel and crozier; paraphyses 1-2 microns wide, filiform or scarcely enlarged in upper part, sparsely or not branched; when the mucilaginous cells are infected, a single hypha "makes contact with the apical papilla on the host''s cell", "and produces an appressed appressorium of much branched, closely packed ends which eventually form a dome over the upper quarter or third of the cell": at the same time, "the cell is penetrated through the apical papilla and a much branched haustorium-like structure is formed just inside the host cell''s wall", growing along it, and eventually reaching the base of the mucilaginous cell, the haustorial hyphae "are closely packed, highly branched in a rivulose manner, thick-walled and slightly gelatinized", and are easily observed in a cotton blue in lactic acid solution
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